Experimental Demonstration of Failure Modes on Bellows Structures Subject to Internal Pressure

2017 ◽  
Author(s):  
Masanori Ando ◽  
Hiroki Yada ◽  
Kazuyuki Tsukimori ◽  
Masakazu Ichimiya ◽  
Yoshinari Anoda
Keyword(s):  
Internal Pressure ◽  
Evaluation Method ◽  
Failure Modes ◽  
Difficult Problem ◽  
Maximum Pressure ◽  
Test Results ◽  
Element Analysis ◽  
Complex Deformation ◽  
Explicit Analysis ◽  
Pressure Failure

In this study, in order to develop the evaluation method of the pressure toughness of bellows structures under the beyond design base event, the pressure failure tests and finite element analysis (FEA) of the bellows structures subjected to internal pressure were performed. Since the several tests and FEA results were reported previously by current authors, the additional tests were performed by the specimen simulating the real setting situation in the actual plant and for demonstrating the plain failure modes. Test specimens consist of the single and double ply bellows made of SUS304 were used. Total five specimens were tested, and one specimen was attached the guard pipe around the bellows to simulate the actual situation in the plant to confirm the effect of the neighbor structures to the ultimate toughness. The maximum pressure obtained in all tests were over 10 times larger than the estimated results of limiting design pressure based on in-plain instability by the EJMA standards; although the test specimens were pressurized exceed the pressure of buckling deformation. Because it is very difficult problem to simulate the inversion of the convolution accompanied convolutions contact for FEA with implicit method, FEA with simplified technique and explicit analysis were performed to simulating the complex deformation of the test specimen, and then these results were estimated in some procedures to compare with the test results. Three failure modes identified in the tests, however, the complex deformation behavior make it difficult to simulate by ordinary FEA procedure and to estimate the ultimate toughness of the bellows structures under the internal pressure. Therefore several kinds of idea for evaluating the ultimate toughness of the bellows structures were execute and suggested.

Experimental Study on the Deformation and Failure of the Bellows Structure Beyond the Designed Internal Pressure

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Masanori Ando ◽  
Hiroki Yada ◽  
Kazuyuki Tsukimori ◽  
Masakazu Ichimiya ◽  
Yoshinari Anoda
Keyword(s):  
Internal Pressure ◽  
Evaluation Method ◽  
Failure Modes ◽  
Ductile Failure ◽  
The Other ◽  
Element Analysis ◽  
Complex Deformation ◽  
Pressurized Water ◽  
Deformation And Failure ◽  
Other Hand

Bellows structure is used to absorb the thermal expansion maintaining the boundary of the inside to outside, and it is applied to constitute the containment vessel (CV) boundary of the nuclear power plant. In this study, in order to develop the evaluation method of the ultimate strength of the bellows structure subject to internal pressure beyond the specified limit, the failure test and finite element analysis (FEA) of the bellows structure were performed. Several types of the bellows structure made of SUS304 were tested using pressurized water. The failure modes were demonstrated through the test of five and six specimens with six and five convolutions, respectively. Water leakage was caused by contact of the expanded convolution and the neighbor structure in the specimens with the shipping rod mounts. On the other hand, local failure as leakage in the deformation concentrated location and ductile failure as burst in the expanded convolution were observed in the specimen without shipping rod mounts. The maximum pressures in the test observed local and ductile failure were over ten times larger than the estimated values of the limited design pressure for in-plane instability by the EJMA standard. To simulate the buckling and deformation behavior during the test, the implicit and explicit FEA were performed. Because the inversion of the convolution accompanied by convolution contact observed in the test was too difficult a problem for implicit analysis, the maximum pressures in the step of solution converged were compared to the maximum pressures in the tests. On the other hand, explicit analysis enabled to simulate the complex deformation during the test, and the results were evaluated considering ductile failure to compare the test results.

Experimental and theoretical study of sandwich composites with Z-pins under quasi-static compression loading

2021 ◽  
pp. 136943322110073
Author(s):  
Erdem Selver ◽  
Gaye Kaya ◽  
Hussein Dalfi
Keyword(s):  
Vinyl Ester ◽  
Failure Modes ◽  
Critical Role ◽  
Sandwich Composites ◽  
Test Results ◽  
Compressive Properties ◽  
Element Analysis ◽  
Static Compression ◽  
Quasi Static Compression ◽  
Good Agreement

This study aims to enhance the compressive properties of sandwich composites containing extruded polystyrene (XPS) foam core and glass or carbon face materials by using carbon/vinyl ester and glass/vinyl ester composite Z-pins. The composite pins were inserted into foam cores at two different densities (15 and 30 mm). Compression test results showed that compressive strength, modulus and loads of the sandwich composites significantly increased after using composite Z-pins. Sandwich composites with 15 mm pin densities exhibited higher compressive properties than that of 30 mm pin densities. The pin type played a critical role whilst carbon pin reinforced sandwich composites had higher compressive properties compared to glass pin reinforced sandwich composites. Finite element analysis (FE) using Abaqus software has been established in this study to verify the experimental results. Experimental and numerical results based on the capabilities of the sandwich composites to capture the mechanical behaviour and the damage failure modes were conducted and showed a good agreement between them.

Failure Modes of American Petroleum Institute 12F Tanks With a Rectangular Cleanout and Stepped Shell Design

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Eyas Azzuni ◽  
Sukru Guzey
Keyword(s):  
Internal Pressure ◽  
Stress Analysis ◽  
Failure Modes ◽  
American Petroleum Institute ◽  
Buckling Analysis ◽  
Vacuum Pressure ◽  
Maximum Pressure ◽  
Elastic Buckling ◽  
Shell Design ◽  
Nonlinear Geometry

The design and fabrication of shop-welded and prefabricated relatively small tanks, when compared to field-welded tanks, used in the upstream segment of the oil and gas industry is governed by the American Petroleum Institute specification 12F (API 12F). This study explores the changing designs of API 12F tanks to include a new rectangular cleanout design with reinforcement as shell extension internally of cleanout frame and a stepped shell design. This study also investigated the introduction of two additional tank sizes in addition to existing eleven tank sizes in the current 12th edition of API 12F. The adequacy of the new design changes and proposed tank designs were verified by elastic stress analysis with nonlinear geometry, elastic–plastic stress analysis with nonlinear geometry, and elastic buckling analysis to verify their ability to operate at a design internal pressure of 16 oz/in2 (6.9 kPa) and maximum pressure during emergency venting of 24 oz/in2 (10.3 kPa). A vacuum pressure of 1.5 oz/in2 (0.43 kPa) was also investigated using the elastic buckling analysis. The stress levels and uplift of the tanks are reported in this report to provide insights into the behavior of proposed API 12F tanks exposed to higher internal pressure and vacuum pressure.

Experimental Research and Finite Element Analysis of Concrete-Filled Steel Box Columns with Longitudinal Stiffeners

2011 ◽  
Vol 287-290 ◽  
pp. 1037-1042 ◽  
Author(s):  
Jun Guang Zhang ◽  
Yong Jian Liu ◽  
Jian Yang ◽  
Kai Lei Xu
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Local Buckling ◽  
Steel Tube ◽  
Steel Plates ◽  
Thin Wall ◽  
Test Results ◽  
Element Analysis ◽  
Longitudinal Stiffeners ◽  
Box Columns

For further study of mechanical properties of concrete-filled steel box columns (CFSBCs) with longitudinal stiffeners, axially loading tests of CFSBCs with longitudinal stiffeners was conducted to obtain their ultimate bearing capacity and failure modes. The test results were compared with those of hollow steel box columns with longitudinal stiffeners. Cross section of the test specimen was scaled from a chord member of Dongjiang Bridge. The experimental results show that failure mode of CFSBCs with longitudinal stiffeners is local buckling of steel plates, which is different from that of concrete-filled thin wall steel tube columns with longitudinal stiffeners. Although longitudinal stiffeners can prevent global buckling of steel plates, the effect is less obvious than that of concrete-filled thin wall steel tube columns. Meanwhile, three-dimensional finite element models (FEM) of the specimens were modeled using computer program ANSYS to obtain bearing capacities and load-strain curves. The FEM results coincide quite well with the test results. Further, influence of width to thickness ratio on mechanical behavior of CFSBCs was analyzed using FEM.

Researches on the Test of Web Local Failure Modes and Related FEA Study

2017 ◽  
Author(s):  
Wenyu Xiao ◽  
Bingbing Liang
Keyword(s):  
Failure Mechanism ◽  
Carrying Capacity ◽  
Nuclear Power ◽  
Evaluation Method ◽  
Failure Modes ◽  
Steel Structure ◽  
Local Failure ◽  
Steel Beam ◽  
Test Results ◽  
Local Yielding

In the analysis of structure steel beam member of mechanical module and piping support in nuclear power plant, beam web shall be analyzed complying with the ASME III NF requirements against web local failure including web local yielding, web local crippling, web sideway buckling and web compression buckling when the beam is subjected to concentrated loads. Referring to the H Type steel structure beam of China GB code; this paper researches the tests of carrying capacity related to the above mentioned local failure mechanism. The results could show that the evaluation method of web local failure mechanism in ASME III NF cover the China GB code steel structure member on one hand; And on the other hand, the results could show the rationalities of the sectional dimension design of the member and the rationality of the beam span. And based on the analysis of the test results, reasonable suggestions could made for the above mentioned member dimension design and beam span design.

Experimental Study on Ultimate Strength of Single and Double Type Bellows Under Internal Pressure

2016 ◽  
Author(s):  
Masanori Ando ◽  
Hiroki Yada ◽  
Kazuyuki Tsukimori ◽  
Masakazu Ichimiya ◽  
Yoshinari Anoda
Keyword(s):  
Internal Pressure ◽  
Fast Reactor ◽  
Evaluation Method ◽  
Safety Margin ◽  
External Pressure ◽  
Element Analysis ◽  
Primary Coolant ◽  
Containment Vessel ◽  
Safety Margins ◽  
Intermediate Heat Exchanger

Containment vessel is an important structure to prevent a significant and sudden radioactive release, however, the safety margin of the containment vessel against the internal or external pressure are not numerically clarified. Namely, the safety margins due to the relationship of the ultimate toughness of containment vessel structures and maximum design pressure is not clear. Indeed, to clarify the progress of the events under the beyond design basis events (BDBE) and to design the BDBE countermeasure equipment, it is necessary to evaluate the pressure toughness of containment vessel adequately. The containment vessel of fast reactor is composed of the various structures, and one of the thinnest boundary structures is bellows structure to absorb the thermal expansion of the coolant piping penetrating the containment vessel. In addition to the containment vessel boundary, evaluating the pressure toughness of reactor coolant and gas boundary is also important because of same reason of that in the containment vessel boundary. In the primary coolant and gas boundary, the cover gas bellows of the intermediate heat exchanger in fast reactor is one of the thinnest structures and has important role when the progress of the BDBE is considered. Therefore, in order to develop the evaluation method of the pressure toughness of bellows structure under the BDBE, the pressure failure tests and finite element analysis of the bellows structure subjected to internal pressure were performed in this study.

Experimental Investigation and Nonlinear Finite Element Analysis of U-Shaped Steel-Concrete Composite Beam

2012 ◽  
Vol 166-169 ◽  
pp. 477-481
Author(s):  
Wen Hu Li ◽  
Feng Hua Zhao
Keyword(s):  
Finite Element Analysis ◽  
Experimental Investigation ◽  
Finite Element ◽  
Composite Beam ◽  
Failure Modes ◽  
Theoretical Calculations ◽  
Nonlinear Finite Element Analysis ◽  
Nonlinear Finite Element ◽  
Test Results ◽  
Element Analysis

U-shaped steel –concrete composite beam is a new form of structure components. Through the test of three groups of specimens, the failure modes of structure components, the strain distribution of cross-section, and the load –deformation relationship are analyzed. A preliminary understanding of mechanical characteristics and deformation performance is got from the experimental investigation. The composite beam element is used to conduct nonlinear Finite Element Analysis. Based on the theoretical calculations and experimental investigation, a practical formula of U-shaped steel- concrete composite beam deformation is established. Moreover, the calculated result is in good agreement with the test results.

A Simplified Fatigue Assessment Method for ASME VIII-2

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Jun Shen ◽  
Mingwan Lu ◽  
Heng Peng ◽  
Yinghua Liu ◽  
Zhiwei Chen
Keyword(s):  
Evaluation Method ◽  
Failure Modes ◽  
Economic Cost ◽  
Material Design ◽  
Assessment Method ◽  
Element Analysis ◽  
Design Factor ◽  
Screening Criteria ◽  
Detailed Assessment ◽  
Fatigue Evaluation

Abstract Fatigue is one of the most common and important failure modes in pressure vessel. ASME VIII-2 provides three screening criterion and three detailed assessment method for fatigue failure. With the decrease of material design factor and the extension of fatigue curve to high cycle, the applicable scope of the three screening criteria become relatively smaller and the economic efficiency is also reduced. Meanwhile, the three fatigue evaluation methods given in ASME VIII-2 Code are all based on detailed numerical calculations (such as finite element analysis (FEA)). Both economic cost and requirements of technical personnel of engineers are higher. In this paper, a simplified fatigue evaluation method is proposed, which gives simple implementation procedures and relatively conservative fatigue evaluation results. Compared with the screening criteria method A, the main advantage is that the scope of its application is wider, that is: (1) the number of significant load cycle can be considered is extended from 1000 to 105; (2) there is no upper limit to the range of pressure fluctuation, which is 20% in method A. Compared with the screening criteria method B, the main advantage is that this method is much simpler and for most materials, design fatigue curves are not required during calculation and evaluation. Compared with the three detailed assessment methods given in ASME VIII-2, this method is very convenient and does not require detailed FEA. The method proposed in this paper can simplify the evaluation process of fatigue analysis in a certain range and provide a more cost-effective engineering assessment method.

Limit Load Analysis of As-Fabricated Pipe Bends With Low Ovality Under In-Plane Closing Moment Loading and Internal Pressure

2018 ◽  
Author(s):  
Sherif S. Sorour ◽  
Mostafa Shazly ◽  
Mohammad M. Megahed
Keyword(s):  
Internal Pressure ◽  
Failure Modes ◽  
Bending Moment ◽  
Limit Load ◽  
Element Analysis ◽  
Pipe Bend ◽  
Bending Process ◽  
Piping Systems ◽  
Geometrical Imperfections ◽  
Pipe Bending

Pipe bends are critical components in piping systems where their failure modes are quite different from straight pipes. The objective of the present work is to investigate the limit loads of pipe bends with actual As-fabricated shape obtained from pipe bending process as compared to bends with Ideal and Assumed imperfect shapes. The present work is conducted by using nonlinear finite element analysis and is performed in two steps. The first step is achieved by simulating rotary pipe bending process with ball mandrel to obtain the actual as-fabricated shape of the 90° pipe bend. The process simulation was verified against published experimental data. In the second step, the pipe bend is subjected to different combinations of simultaneous loads consisting of internal pressure and In-plane closing bending moment. Results are provided for limit load curves for pipe bends with as-fabricated geometries and bends with ideal shape and assumed geometrical imperfections.

scholarly journals Optimization and Mechanical Properties of Fabricated 2D Wood Pyramid Lattice Sandwich Structure

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 607
Author(s):  
Dongxia Yang ◽  
Changsheng Fan ◽  
Yingcheng Hu
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structure ◽  
Failure Modes ◽  
High Strength ◽  
Test Results ◽  
Element Analysis ◽  
Compression Performance ◽  
Truss Core ◽  
Unit Cells ◽  
Better Than

In order to obtain a lightweight, high strength, and large design space wooden sandwich structure to meet the needs of modern wooden buildings, the mechanical properties of a fabricated 2D wooden pyramid lattice sandwich structure were studied. In this paper, the mechanical and compressive properties of the specimens with different arrangement of Lattice Sandwich unit cells are studied. The upper and lower panels and core materials are made into a single unit cell by inserting glue, and the prefabricated 2D wooden pyramid lattice truss core sandwich structure is prepared by the mortise tenon splicing method. The results show that the arrangement of the unit cells in the specimen has a significant effect on the bearing capacity, energy absorption, and failure mode of the specimen, and the flat compression performance of the panel-reinforced specimen is better than that of the specimen with unreinforced veneer. The results of finite element analysis are consistent with the test results. The main failure modes are core fracture and panel cracking. These results provide a theoretical basis for the system design of wood-based lattice sandwich structure in the future.

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